CYP2C19 and transient ischemic attack: The incidence of stroke and transient ischemic attack within 90 days was 11 cases, including 7 cases of CYP2C19 gene deletion, 4 cases of CYP2C19 gene carriers, 4 cases of vertebrobasilar artery extracranial stenosis, and 7 cases of vertebrobasilar artery intracranial stenosis.